Two posters made a remark about "fake". Not so. Here's how it usually works: the girl farts out empty, then the camera moves up to her face saying something while someone blows her ass full again using that plastic pipe we saw here @ 7:31. But in this video they just stopped & restarted the camera: @2:46, 3:09, 3:29, 6:10, 7:40, etc.
If they want that smoke to show, they'll have to use a black, patternless background, and then backlighting on the smoke.

The very definition of a boring day - 2 women with nothing better to do than lick each other's assholes and smell each others farts. One girl smokes a cigarette and literally blows smoke up the other one's ass.